What’s Next for Lorqess?

Arena Pharmaceuticals’ obesity drug candidate Lorqess was summarily dismissed by an FDA advisory committee yesterday, leaving many to wonder: what’s next? The panel had few questions about the drug’s efficacy, but voted it down in large part due to worrisome data showing high doses of the compound caused tumors in rats. So is there a way forward for Lorqess? Or will it be relegated to the annals of Dead-in-the-Water Obesity Drugs?

Analysts have mixed opinions on how Arena could get itself out of this pickle. Some think the biotech could salvage the drug if it could offer up one key piece of information: the mechanism of action of the tumors seen in rats.

In a call with analyst this morning, Arena suggested it had already proven this point, noting that the presentation by Gary Williams, an expert on the mechanisms of carcinogenesis, showed that the rat findings did not translate to humans. “It’s a shame there were no carcinogenicity experts on the panel,” Arena’s president and CEO Jack Lief said. “My view is they were having difficulty understanding our presentation.” The company didn’t offer much guidance as to what other data it had on hand or other studies it could conduct to close the book on the issue.

Other industry watchers are focused on another issue the panel had: the unrealistic patient population in which Arena chose to test lorcaserin. They thought the people in the trial were not close enough to the kind of folks who would really be taking the drug in the real world–in other words, people with the kind of health complications typically associated with obesity.

Later this year, Arena will release data from its BLOOM-DM study, which is meant to test the drug’s efficacy in diabetics. Cowen & Co’s Phil Nadeau suggested that trial may satisfy the agency’s patient population worries.

But JPMorgan’s Cory Kasimov was less optimistic about the diabetes data providing reassurance about the drug’s safety. “With only 604 patients randomized to either drug or placebo (not to mention dropouts), it’s just way too small to generate any satisfactory answers,” Kasimov said in a note last night. Not to mention the drug has to show it still works in this tough-to-treat group.

BMO Capital analyst Jason Zhang suggested that another path forward would be for Arena to conduct a Phase II proof of concept trial of lorcaserin and phentermine in the right patient population (i.e. diabetics). He thinks the combination should be more effective at helping people shed weight than lorcaserin alone, and notes that data from Arena and academic researchers suggest the duo would not have the same heart issues that sank the fenfluramine-phentermine combo. And improved weight loss might shift the risk-to-benefit ratio enough to make FDA more comfortable with approving the drug. The quandary, however, is that even if a combination trial was effective, chances are slim that anyone would cough up the money for a large, Phase III study.

The bottom line: doctors are unlikely to be writing out prescriptions for Lorqess any time soon. Analysts have taken sales estimates for the drugs off of their spreadsheets for the near future, with most saying 2013 is the most realistic timeframe for it to make it to the market.

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